The National Insurance Act, 1911, compelled
local authorities to establish TB hospitals and, by 1920,
the Middlesex County Council (MCC)
had an urgent need for TB beds. It had purchased a piece of land
in Essex on which to build a sanatorium, but the outbreak of war
delayed the project. Until its own sanatorium could be built, the
MCC made arrangements to send its patients to Clare Hall Hospital.

The No. 1 Australian Auxiliary Hospital
on the Harefield Park estate had closed in 1919, but the owners of the estate, the
Billyard-Leakes, who had been living at the nearby Black Jack's Mill,
felt unable to move back into their old home. Instead, they sold the
estate for £20,000 to the MCC.

Harefield, being one of the highest points
in Middlesex, some 290 feet (90 metres) above sea-level, could provide
abundant fresh air and sunlight - ideal for the favoured open air
treatment for the disease. The MCC sold their site in Essex
and the money was put towards the purchase of Harefield Park estate.

Work began on the site in 1920. The
Australian huts remained, but they were unsuitable for TB patients,
being too close together. Most of them were demolished but
several were re-used in a different configuration, which enabled the
male patients to be segregated from the female, and the children from
the adults. The mortuary and the chapel remained.

The Harefield Sanatorium opened in October
1921 with 250 beds. It looked quite different from the No. 1
Australian Auxiliary Hospital. The patients were accommodated in
six large single-story huts (pavilions). Male patients were at
the north of the site, at least half a mile from the entrance.
Females were to the south, while the children's wards were
nearest to the entrance, with that for boys at the east end and for
girls at the west end. A school room was nearby, connected to the
children's hut by a covered walkway. The former coach house became the Observation Ward, where new patients
were admitted while it was confirmed that they had pulmonary TB.

The House (now known as The Mansion) was
used for medical staff quarters. Matron resided in her own wooden
bungalow, while the Nurses' Home consisted of six huts with cubicles.
The nursing staff comprised 11 Sisters, 17 Staff Nurses and 23
probationers. Altogether the Sanatorium had 110 staff, including
a cook, a laundress, a seamstress, an engineer, a stoker, a lodge
keeper and an ambulance driver. However, the isolated location
and crude living conditions made recruitment of staff difficult.

The Sanatorium had its own farm and
orchards, making it relatively self-sufficient. Geese, turkeys
and 3,000 laying hens were kept, as well as pigs and a few goats.
The kitchen garden provided salad and vegetables.

In 1932 a new Nurses' Home was built to
the south of the old one. In 1933 it was decided to replace the
wooden huts with permanent brick buildings on the site of the female
ward pavilions. The patients were moved to the old Nurses' Home
and the Sanatorium remained operational when building work began in
1935. It was completed in 1937, the last hospital to be built in
Britain before WW2.

The Harefield County Sanatorium was
officially opened in October 1937 by the Duke of Gloucester. The
main building, in a modern 'international' style, was crossbow in shape
- a central block with curved, angled wings to either side of it - across a
north-south axis. It had 378 beds in the two 3-storey wings,
which faced south towards the village. The central section
contained the administrative offices, treatment rooms, an X-ray
Department and, as the MCC were aware of the future role of surgery in
the treatment of TB, an operating theatre. (Reputedly, the
Sanatorium was one of the first places to treat TB patients with
artificial pneumothorax in January 1939.) Behind the central
block, in a separate building to the north, were located the central
kitchen and the main dining room. The building also contained a
concert hall and a recessed chapel at one end. The Observation
Ward, utilities and services were located to the north of the main
block. The Sanatorium had its own water supply and generated its
own electrivity.

The new buildings were connected with
paved roads and there was a new entrance in Hill End Road. New
staff accommodation had been built to the far north of the site.
The Lodge to the old entrance had been pulled down and the
entrance was pedestrianised.

At the outbreak of WW2 the Sanatorium became the Harefield Emergency Hospital, an Emergency Medical Service base hospital for St Mary's Hospital
in Praed Street. Thirteen prefabricated huts of corrugated iron
lined with asbestos and with pitched roofs were built. Each
contained 24 beds. The huts were heated by three coke stoves -
one at each end of the hut and one in the middle. The Hospital
would contain 464 casualty beds. In September 1939, just as the
patients had been transferred from St Mary's Hospital, an outbreak of
meningococcal meningitis occurred at the Harefield site.
Fortunately, a new drug - sulphanilamide - was available and
no-one died (the infection previously had had a 70-90% mortality).

During 1940 sixteen more huts were added,
made of concrete with flat roofs. An Almoner's Department was
established. In November the Hospital received a large influx of
patients - servicemen from the British Expeditionary Force in France
who had contracted TB. Little could be done and mortality was
high.

During the Blitz in 1941 air-raid victims
in central London were treated at St Mary's Hospital and then bussed
out to Harefield. Later, military cases were flown to Northolt to
be transferred to Harefield. Dealing with war casualties, the
Hospital enlarged its scope for general and thoracic surgery.

At its peak the Hospital had 1200 beds.
Patients included Polish servicemen and Free French forces.
Later, German naval prisoners-of-war also received treatment.

Matron's old wooden bungalow was used as a 'cottage laboratory' by Prof. Alexander Fleming while he studied the effect of penicillin on TB.

The Hospital received no bomb damage
during the war and, in 1945, St Mary's Hospital returned to Praed
Street. By 1945 penicillin had become generally available for the
treatment of TB and other infections. The government had
undertaken to provide treatment in Military Units for all servicemen
with TB, and one such Unit was established at Harefield. Located
at the north of the site, it had 6 wards with 24 beds in each.

Very little cardiac surgery had been possible during the war, but the first thoracic surgeon appointed to the Hospital, Mr Thomas Holmes Sellors, performed the first valvotomy, an operation for the direct relief of pulmonary stenosis in a patient with Fallot's tetralogy
(a congenital heart defect) in December 1947. Pioneering surgical
techniques were also developed to treat disease and injury of the
oesophagus. A service to treat carcinoma of the oesophagus was
established in the late 1940s.

In 1948 the Hospital joined the NHS under
the control of the Harefield and Northwood Hospital Group, part of the
North West Metropolitan Regional Hospital Board. It was renamed
Harefield Hospital and became a general hospital but still had a
Thoracic Surgery Unit, now treating all kinds of chest diseases (during
the 1950s, as the incidence of TB fell, the TB Clinics were renamed
Chest Clinics).

By the 1960s the farm, piggery and kitchen
garden had gone. The 'cottage laboratory' had been demolished and
TB had all but disappeared. The Hospital became one of two
hospitals (the other was Clare Hall Hospital)
under the control of the North West Metropolitan Regional Hospital
Board which treated chest diseases, as well as medical and surgical
general cases.

In 1960 a Mayo-Gibbon heart-lung machine was purchased and first used in 1961 during a valvotomy
on a 12-year-old girl with Fallot's tetralogy. A Respiratory
Physiology Department was established in 1961. In 1964 a new
Physiotherapy Department opened, and work began to build a new X-ray
Department and a twin operating theatre suite just south of the east
ward wing. A new Pathology Department opened in 1965.

The thoracic work became more specialised. By 1967 the Thoracic Surgery Unit had 80 beds. A pacemaker
service was established. A new road and car park were built on
the north side of the site. The new X-ray Department and
operating theatres opened in July.

By the
early 1970s, while thoracic patients were still being investigated and
treated, the number of cardiac operations had trebled. The
Hospital became recognised as the Regional cardiothoracic centre.
In 1973 Mr. Magdi Yacoub
was appointed
as a consultant cardiac surgeon and established a Paediatric Surgical
Unit with 9 beds. Clare Hall Hospital closed in 1974 and its
thoracic work
transferred to Harefield Hospital, which at this time had 400 beds.

In 1976 a two-stage operation was
pioneered for anatomical correction in children with 'transposition of
the great vessels' (the aorta and pulmonary artery leave the wrong side
of the heart). (Usually undertaken in the first few weeks of a
child's life, the first one-stage operation on a neonate was performed
in 1982.) By 1979, although the Hospital still accommodated
general medical and surgical cases, it was increasingly specialising in cardiothoracic surgery and medicine.

In 1980 the X-ray Department was extended
at the cost of £500,000. The new unit was opened by the
Minister of Health and contained equipment for special investigations
and interventions, such as cardiac catheter, angiography and
ultrasound. In 1980, under the leadership of Magdi Yacoub,
surgeons performed Harefield's first heart transplant. In 1983 Mr.
Yacoub performed the first combined heart and lung transplant worldwide (lung transplant alone was less
successful than a heart-lung transplant). The following year a
baby, less than one month old, received a heart transplant. In
1987 the first 'domino' procedure was undertaken, whereby a patient
with cystic fibrosis (who had a healthy heart) underwent a heart-lung
transplant, while a second patient received the first patient's heart.
In 1988 the Eric Morecambe Department of Cardiology and a new
Intensive Care unit were opened by Sarah Ferguson, the Duchess of York.
By this time the Hospital had 172 beds. In July 1989 the
Princess Royal opened the Playdrome and extension to the children's ward.

In 1995 the Hospital, together with the
National Heart and Lung Institute of Imperial College, pioneered the
development of a device - an artificial left ventricle - to assist the
heart to pump.

In 2000 the Harefield Research Foundation
was established to continue the work of Prof. Yacoub, who was knighted in 1991. (Located in the
Heart Science Centre, it was renamed the Magdi Yacoub Institute in
February 2004.)

In 2003 the Anzac Centre opened. Built at a cost of £4m, it
replaced some of the oldest accommodation at the Hospital. It
contains the Out-Patients Department, the Respiratory Physiology
Department (for lung function tests), the Echocardiology and Nuclear
Medicine Departments, the transplant clinic and two cardiac operating
theatres.

Present status (March 2010)

Harefield Hospital remains operational.
The Grade II*- listed mansion survives, as well as its two flanking
buildings (the coach house and stables).

The main gate with a police station on the right.
The central block with the main entrance to the Hospital (left). The curve of the wings can just be discerned (right).

The north block contains the chapel and the canteen ('The Hungry Hare') (left) . Looking west, the main entrance is on the left, with the north block on the right (right).

Sculptural art at Harefield: a statue by Anthony Gormley
(left) was unveiled by Gordon Brown, Chancellor of the Exchequer, in
March 2005. The statue is located on the roof of the Heart
Science Centre. Mr Brown returned again in November 2008, now the Prime
Minister, to unveil a statue of Prometheus
(right), a gift of members of the Praxiteleion, a group of Greek
hospitals and diagnostic centres engaged in similar work to the Magdi
Yacoub Institute.
The refurbished Thoracic Unit under construction to the south of the main hospital.

The
land to the north of the current Hospital once housed the temporary
pavilions for male patients suffering from tuberculosis. The huts
were demolished when the permanent Hospital was erected, but rebuilt
during WW2 as part of the Emergency Medical Service Hospital.
They survived until the 1980s, when the area became a Medipark. In February 2010 developers began to clear the land with a view to building an apartment block on the site.

ReferencesCobbett L 1930 The decline of tuberculosis and the increase in its mortality during the war. Journal of Hygiene 30, 79-103.